In computer-assisted knee arthroplasty, for example, an incision block is commonly used, wherein the incision block includes an incision guide for defining an incision plane. A localization reference is attached to the incision guide, wherein the localization reference can be spatially adjusted, e.g., rotated, in order to allow the localization reference to be optimally visible for various applications and/or configurations. By means of the localization reference and a medical navigation system, an attempt is made to position the incision block such that the incision guide comes to rest in a planned incision plane.
A guiding block for use in surgical incisions is known from WO 2004/017843 A1, including a fixation part that is fastened to a bone, and a guiding part that can be moved relative to the fixation part and adjusted in its position. Light-emitting diodes are used to indicate the position of the guiding part. DE 102 07 035 A1 discloses a template for guiding a surgical treatment tool, including a fastening means for fixing the template to a bone to be treated via three bone screws.
An adjustment means can be used to set the incision plane in the ‘slope’, ‘varus-valgus’ and ‘resection depth’ degrees of freedom typical for bones, in accordance with the presets of the navigation system (target incision plane). However, this can be problematic when the bone incision block (in particular the adjustment means) is fastened to the bone such that the operating elements are not clearly assigned to the degrees of freedom of the incision plane defined by the incision guide. In such cases, for example, operating an element may result in a change in more than one degree of freedom, or two operating elements may need to be activated in order to adjust in one degree of freedom. Finding the most favorable way to complete the adjusting process in the shortest period of time then depends largely on the knowledge and experience of the operator. Although the target incision plane is preset by navigation, it is often difficult to set the incision guide in accordance with target incision plane and/or presets without assistance, especially if the incision block is arranged unfavorably on the bone. If unfavorably arranged on the bone, an iterative procedure may be necessary, since direct adjusting using the interdependence of the functional members is not possible.